To prevent a liquid such as water from entering the inside, for example, of a wet suit or a wader while the opening and closing portion or the opening is closed, a slide fastener having waterproof property (hereinafter, referred to as a “waterproof slide fastener”) is often used at the opening and closing portion or the opening. Note that, herein, the waterproof property means the resistance to passage of not only water but also a liquid other than water. Some waterproof slide fasteners not only prevent the entry of liquid but also exert airtightness to prevent the entry of gas.
A waterproof slide fastener usually includes a pair of right and left fastener stringers in which element rows are formed on waterproof tapes each having a waterproof layer, and a slider that can slide along the element rows. The right and left element rows engage with each other such that the facing edge parts of the right and left waterproof tapes are in close contact with each other. This prevents water from entering the rear face side of the tape from the front face side of the tape (or entering the front face side of the tape from the rear face side of the tape) through a space between the right and left waterproof tapes.
Note that, hereinafter, the vertical direction is the lengthwise direction of a waterproof fastener tape, and is the same as the slide direction in which the slider slides. Especially, the direction in which the slider slides to engage the right and left element rows with each other in order to close a waterproof slide fastener is referred to as an upward direction, and the direction in which the slider slides to disengage right and left fastener elements in order to open the waterproof slide fastener is referred to as a downward direction. Furthermore, the horizontal direction is the width direction of the waterproof fastener tape and is the direction parallel to the tape face of the waterproof fastener tape and perpendicular to the lengthwise direction of the tape. Furthermore, the longitudinal direction is the direction of the front and rear faces of the waterproof fastener tape and perpendicular to the tape face of the waterproof fastener tape. Especially, the direction on the side of the waterproof fastener tape on which a tab of the slider is placed is the frontward direction and the direction on the opposite side is the rearward direction.
For example, JP 2005-237577 A (Patent Document 1) and JP 2007-167220 A (Patent Document 2) each disclose a waterproof slide fastener.
As illustrated in FIG. 8, the waterproof slide fastener described in Patent Document 1 is a waterproof slide fastener with waterproof property in which covering both of the front and rear faces of each of woven or knitted fastener tapes 110 with a thermoplastic elastomer causes the fastener tape to be waterproof; through-holes 114 penetrating the front and rear faces are provided at positions at which fastener elements are attached to the end edges 111a of the fastener tape; the fastener elements each made of a thermoplastic resin and formed of a coupling head 122, a neck part 123, a body part 124, a shoulder part 125, and a leg part 127 are attached to the end edge 111a with injection molding; each of the through-holes 114 is covered with leg parts 127 of the fastener element; and a connecting portion 121c connects the leg parts 127 on the front and rear faces through the through hole.
As illustrated in FIG. 9, the waterproof slide fastener described in Patent Document 2 is a waterproof slide fastener in which a whole fastener tape 2 is covered with an elastomer; a through-hole 208 is provided on the lateral edge of the fastener tape 202; a fastener element 203 formed of a coupling head 210, a neck part 212, an engaged projecting portion 213, a leg part 214, and a tongue portion 216 is injection molded so as to cover the through-hole 208; and a reinforcement part 218 projects on a side of the leg part 214 in the lengthwise direction of the through-hole 208 while covering a part of the through-hole 208 and surrounding the through-hole 208. The reinforcement part 218 prevents a through-hole 208 from being exposed even when the fastener tape 202 is bent. This allows the waterproof slide fastener to maintain watertightness and airtightness.